I have been a Professor in theoretical nuclear physics at the University of Oslo since May 1 2001. I was an associate professor at the same university in the period January 1 1999 to April 30 2001. I got my PhD in theoretical nuclear physics in December 1993 at the University of Oslo and a Siv. Ing. (Master of Science equivalent) degree in March 1988 at the Technical University of Norway (NTH) in Trondheim. In the period August 1989 till December 1993 I was a research assistant (PhD studies) at the University of Oslo and a research associate in the period January 1 till September 30 1994 at the same place. In the period October 1 1994- December 1998 I was a post-doctoral fellow at the European Center for theoretical studies in nuclear physics, ECT* , in Trento, Italy and at the Nordita in Copenhagen, Denmark. In December 2000 I shared the University of Oslo Excellence in Teaching Award with Arnt Inge Vistnes. In 2007 I became a fellow of the American Physical Society. In 2008, our team, David Dean, Gaute Hagen, Thomas Papenbrock and myself received the Oak Ridge National Laboratory award in the category for "Scientific Research" for our development and implementation of coupled-cluster theory for medium mass and neutron-rich nuclei. My research interests span most of the areas decribed under these pages on computational physics and computational quantum mechanics in particular. The main focus has been and is on many-body methods for nuclear structure problems, but I have also done and continue to do research on Bose-Einstein condensation and the structure of quantum dots, in addition to studies of the mathematical properties of various many-body methods. In essence, my research can be summmarized under the topic studies of algorithms and methods for solving Schroedinger's equation or Dirac's equation for many interacting particles. I am a theoretical physicist with a strong interest in computational physics and many-body theory in general, and the nuclear many-body problem and nuclear structure problems in particular. This means that I study various methods for solving either Schrödinger's equation or Dirac's equation for many interacting particles, spanning from algorithmic aspects to the mathematical properties of such methods. The latter also leads to a strong interest in computational physics as well as computational aspects of quantum mechanical methods. A large fraction of my work, in close collaboration with colleagues at Michigan State University, the University of Oslo, Oak Ridge National Laboratory as well as many other institutions worldwide, is devoted to a better understanding of various quantum mechanical algorithms. This activity leads to strong overlaps with other scientific fields. Although the main focus has been and is on many-body methods for nuclear structure problems, I have also done, and continue to do, research on solid state physics systems in addition to studies of the mathematical properties of various many-body methods. The applications to many-body problems in nuclear physics lead also to many interactions with experimentalists and various experimental programs. The theories I participate in developing, have as final aims to be able to explain correlations in complicated many-body systems like nuclei and dense nuclear matter. Why the nuclear many-body problem, you may ask. Well, for me, to understand why matter is stable, and thereby shed light on the limits of nuclear stability, is one of the overarching aims and intellectual challenges of basic research in nuclear physics and science. To relate the stability of matter to the underlying fundamental forces and particles of nature as manifested in nuclear matter is central to present and planned rare isotope facilities.